A hostname verification bypass in GnuTLS v3.8.13 allows attackers to circumvent the Common Name fallback mechanism and eavesdrop on communications via a crafted certificate.

Metrics

No CVSS v4.0

Attack Vector Network

Attack Complexity High

Privileges Required None

Scope Unchanged

Confidentiality Impact Low

Integrity Impact High

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploitation none

Automatable no

Technical Impact partial

Affected Vendors & Products

Vendors Products
Gnu
  • Gnutls

No data.

No data.

References
Link Providers
https://gist.github.com/lkloliver/f98ec3de1a871fdfc02b70b8b9ba7642 cve-icon cve-icon cve-icon
https://gitlab.com/gnutls/gnutls/-/issues/1802 cve-icon cve-icon cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2026-88647 cve-icon
https://www.cve.org/CVERecord?id=CVE-2026-88647 cve-icon
History

Mon, 19 Oct 2026 16:30:00 +0000

Type Values Removed Values Added
References
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

 ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Mon, 19 Oct 2026 15:30:00 +0000

Type Values Removed Values Added
References
Metrics cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

 cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Sat, 10 Oct 2026 03:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-297
Metrics cvssV3_1

{'score': 7.4, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N'}

 ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'}

Fri, 09 Oct 2026 07:45:00 +0000

Type Values Removed Values Added
First Time appeared Gnu
Gnu gnutls
Vendors & Products Gnu
Gnu gnutls

Fri, 09 Oct 2026 04:00:00 +0000

Type Values Removed Values Added
Weaknesses CWE-640

Fri, 09 Oct 2026 00:15:00 +0000

Type Values Removed Values Added
Title GnuTLS 3.8.13 Hostname Verification Bypass Enables Eavesdropping gnutls: gnutls: Information disclosure via hostname verification bypass
Weaknesses CWE-295
References
Metrics threat_severity

None

 cvssV3_1

{'score': 7.4, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N'}

threat_severity

Important

Thu, 08 Oct 2026 19:15:00 +0000

Type Values Removed Values Added
Title GnuTLS 3.8.13 Hostname Verification Bypass Enables Eavesdropping
Weaknesses CWE-640

Thu, 08 Oct 2026 17:00:00 +0000

Type Values Removed Values Added
Description A hostname verification bypass in GnuTLS v3.8.13 allows attackers to circumvent the Common Name fallback mechanism and eavesdrop on communications via a crafted certificate.
References
cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published: 2026-10-08T00:00:00.000Z

Updated: 2026-10-19T15:16:47.855Z

Reserved: 2026-09-10T00:00:00.000Z

Link: CVE-2026-88647

cve-icon Vulnrichment

Updated: 2026-10-10T02:52:28.059Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-10-08T17:17:17.783

Modified: 2026-10-19T16:17:08.333

Link: CVE-2026-88647

cve-icon Redhat

Severity : Important

Publid Date: 2026-10-08T00:00:00Z

Links: CVE-2026-88647 - Bugzilla